Combustion chamber burner throat construction

ABSTRACT

A burner throat that is shaped in accordance with the shape of the combustion chamber in which the throat is installed to afford flame shaping so that the flame is distributed throughout the combustion chamber. A burner throat formed of a plurality of individual segmental bricks, the totality of which define the throat shape. Each brick is shaped in respect to its position in the throat to direct the flame appropriately within the combustion chamber. A burner throat formed at the site of installation with a plurality of appropriately shaped segmental bricks.

United States Patent Binasik et a1.

[54] COMBUSTION CHAMBER BURNER THROAT CONSTRUCTION [72] Inventors: Chester S. Biuuik, Palo Alto; Daniel H. Hudson, San Lorenzo; Temple S. Voorheis,

211 Appl. No.: 1,653

[52] U.S.Cl. ..1l0/l A, 431/187 [51] Int. Cl ..F23m 5/02 [58] fieldofSearch ..ll0/l, 182.5;431/8, 187

[56] References Cited UNITED STATES PATENTS 2,192,682 3/1940 Anderson ..1431/187 X 3,285,315 11/1966 Voorheis ..43l/8 X 1 Feb. 15,1972

Primary Examiner-Edward G. Favors Attomey-Townsend and Townsend [57] ABSTRACT A burner throat that is shaped in accordance with the shape of the combustion chamber in which the throat is installed to afford flame shaping so that the flame is distributed throughout the combustion chamber. A bumer throat formed of a plurality of individual segmental bricks, the totality of which define the throat shape. Each brick is shaped in respect to its position in the throat to direct the flame appropriately within the combustion chamber. A burner throat formed at the site of installation with a plurality of appropriately shaped segmental bricks.

7Claims,6DrawingFigures PATENTEDFEB 15 I972 INVENTORS TEMPLE 5. VOORHEIS DANIEL H. HUDSON CHESTER S. BINASIK ATTORNEYS COMBUSTION CHAMBER BURNER THROAT CONSTRUCTION This invention relates to a burner throat construction for a furnace or like combustion chamber and more particularly to a burner throat configured to afford flame shaping so that the flame substantially totally fills the combustion chamber with which the structure of the invention is used.

Optimum operation of a combustion chamber is achieved by substantially filling the combustion chamber with flame. For example, in combustion chambers of water tube boilers, the interior surface of the combustion chamber is lined with water tubes, and the efficiency and amount of steam production varies in direct proportion to the degree to which the flame fills the combustion chamber and heats each of the tubes uniformly. Firing such combustion chamber through a central burner throat opening requires special care, particularly in combustion chambers having a rectangular cross section. This is so because the typical burner throat produces a flame having a more or less circular cross section, which does not deliver adequate flame to the corners at which the walls of the combustion chamber intersect. The present invention has for its principal object the provision of a burner throat construction that affords flame shaping so that the flame substantially fills the combustion chamber including the comers thereof. This object is achieved by providing a noncircular burner throat that has relieved or outwardly flared portions opposite the comers of the combustion chamber whereby the flame created by the burner can leak out radially of the central axis of the burner throat, thereby to fill the corners of the combustion chamber.

Another object of the present invention is to provide a burner throat construction, the particular shape of which can be readily adapted to existing combustion chambers without modification of the combustion chamber. This object is achieved by providing a burner throat construction that is formed of segmental tiles wherein the shape and position of each tile can be established to achieve the desired flame shaped in accordance with the size of the combustion chamber.

In attaining the previously stated object, the invention provides a plurality of throat tiles or brick that have throat-defining faces which diverge radially outward toward the inner surface of the burner wall in which the throat is installed. Each of the individual tiles or bricks is tapered so that a plurality of such bricks can be fit together to define a complete burner throat structure. By this expedient, the necessity for casting large sections of a burner throat wall is eliminated. In a preferred form of the invention, the outer surfaces of the totality of the arch bricks is circular whereas the inner surface, the active surface as far as flame shaping is concerned, is irregular in accordance with the shape of the combustion chamber.

The foregoing together with other objects, features, and advantages, will be more apparent after referring to the following specification and accompanying drawing in which:

FIG. 1 is a partially diagrammatic elevation view of a combustion chamber provided with a burner throat according to the present invention;

FIG. 2 is a partially diagrammatic plan view of the combustion chamber ofFlG. 1;

FIG. 3 is taken along line 33 and is an elevation view of the burner throat looking axially thereof from the interior of the combustion chamber;

FIG. 4 is a side view of a specific segment of the burner throat taken along 4-4 of FIG. 3;

FIG. 5 is a view of still another segment of the burner throat taken along line 5-5 of FIG. 3; and

FIG. 6 is a view of yet another segment of the burner throat taken along 66 of FIG. 3.

Referring more particularly to the drawing, reference numeral 12 indicates a combustion chamber formed by a front wall 14, a rear wall 16, and sidewalls l8 and 20. The combustion chamber also includes a floor 22 and a roof not shown. The interior surfaces of the walls, roof, and floor delimit the boundaries of the combustion chamber. Front wall 14 has an outer face 24 and an inner face 26 between which extends a burner throat opening 28. Air is supplied to the combustion chamber through throat opening 28 by suitable ducts not shown along a path indicated by arrows 30. Fuel such as oil or the like is supplied through a suitable burner nozzle 32.

Burner throat 28 defines a circular opening 34 at outer face 24 of front wall 14. Opening 34 is concentric with male 32. The outer portion of burner throat 28, that is, the portion between circular opening 34 and a plane intermediate outer face 24 and inner face 26, defines an inwardly diverging frustoconical surface 36 which terminates in a circle at 38 that has a diameter larger than that of circular opening 34. Frustoconical portion 36 permits air traveling along path 30 into the burner throat to expand or diverge uniformly radially outward of the central axis of the throat. The radial divergence is uniform or symmetrical about the central axis of the throat, because circle 38 is concentric with outer circular opening 34.

Although frustoconical surface 36 can be formed by a single refractory body, it is preferred that it be formed by a plurality of refractory tiles 40 which as can be seen in FIG. 3 taper in a radial sense so that the totality of the tiles circumferentially fill the throat opening. In the example shown in the drawing, forty throat tiles are included, as a consequence of which each throat tile tapers at about a 9 angle.

Extending between circle 38 and inner face 26 of wall 14 are a plurality of specially configured refractory bricks 42. Each individual brick 42 has a specific shape so as to form a throat with a shape suitable for substantially filling the combustion chamber. More particularly, bricks 42a which are adjacent to sidewalls 18 and 20 are shaped to guide the flame inwardly so that it does not impinge on the sidewalls which are relatively close to the axis of the throat. With reference to FIG. 4, brick 42a defines adjacent circle 38 a relatively wide throat shape as indicated at 44 and at inner face 26 a relatively confined throat-opening portion indicated at 46. Thus air moving through the throat opposite brick 42a is deflected inwardly along the path indicated by arrow 48, and the flame follows a corresponding path as a consequence of which the flame does not directly impinge on the sidewalls of the combustion chamber. Obviously, the degree to which portion 46 converges with respect to portion 44 of brick 42a can be established at any suitable amount depending on the distance from the throat opening to the wall adjacent which the brick is positioned.

A brick 42b, which is in approximate alignment with and adjacent to the corner formed by the intersection of sidewall 20 and the roof of the combustion chamber, is formed to permit substantial flame to bleed outwardly so as to fill the corner with flame. With reference to FIG. 5, brick 42b flares outwardly from a point 50 adjacent circle 38 to a point 52 on inner wall 26. Consequently, the air moving through the throat past brick 42b causes the flame to bleed or expand outwardly along a path indicated by arrow 54 so that the corner of the combustion chamber opposite brick 42b is supplied with adequate flame.

A brick 42c, positioned at the top of the throat and adjacent to the roof of the combustion chamber, is configured to permit only a slight degree of flame divergence to avoid impingement of the flame on the roof of the combustion chamber, but to permit the flame to expand upward to fill the combustion chamber with flame. Brick 42c, as can be seen from FIG. 6, has a point 56 adjacent circle 38 that lies in the same radial position as the circle to form a smooth transition between frustoconical portion 36 and flame-forming portion of the throat structure. Brick 42c continues smoothly to a point 58 inwardly of circle 38 from which the brick surface has a portion 60 approximately parallel to the central axis of the opening that extends to inner surface 26. The portion of the brick surface between points 56 and 58 permit the flame to spread somewhat and the straight portion 60 deflects the air and the flame somewhat inwardly along a path indicated by arrow 62.

In designing a burner throat embodying the present invention, after the position of the throat in wall 14 is established, the distances from the burner throat to the sidewalls and top and bottom walls are determined as is the location of wall intersection which are typically more remote from the burner throat than wall surfaces. Appropriately shaped bricks 42 are selected to achieve a flame shape to fill the combustion chamber. At regions of the burner throat opposite relatively close combustion chamber walls, bricks of the type designated 42a are installed to deflect the flame inwardly so as to avoid direct flame impingement on the walls. At regions of the throat opposite intersections of the walls, which are typically remote from the burner throat, bricks conforming generally to the shape of brick 42b are installed to permit the flame to diverge or bleed outwardly thereby to fill the corners. At regions of the throat where the burner wall is located intermediate the two extremes just described, bricks of the general form indicated at 42c are installed. Obviously the bricks intermediate the three specific forms shown in the drawings can be installed with different degrees of taper to achieve smooth continuity between various regions in the combustion chamber.

Because the entire burner throat is formed of a plurality of individual bricks, design and fabrication of the throat are expedited. Fabricated is expedited, because instead of relatively massive castings of refractory material, the throat can be formed on the job by placement of the individual bricks at the appropriate positions. Design of the throat is expedited because virtually any shape combustion chamber can be accommodated by appropriately selecting and positioning bricks of various shapes and degrees of divergency or convergency.

Thus it will be seen that the present invention provides an improved burner throat construction that can be adapted to virtually any shape combustion chamber to fill the chamber uniformly with flame. Moreover, the throat of the present invention, since it is constructed of a plurality of relatively small elements, can be readily fabricated on the job.

While one embodiment of the invention has been shown and described, it will be obvious that other adaptations and modifications can be made without departing from the true spirit and scope of the invention.

What is claimed is: v

1. In a combustion chamber bounded by refractory walls through one of which extends a throat opening between the outer and inner surfaces of the one wall to admit fuel and air into the combustion chamber, the improvement comprising a plurality of sectorial refractory bricks so disposed that the totality of said bricks form at least the portion of the throat adjacent the inner surface of the one combustion chamber wall, each said brick having. a flame-shaping surface thereon, the flame-shaping surfaces being disposed in circumferentially spaced relation to one another so that the totality of the surfaces form at least the inner portion of the throat opening, said brick flame shaping surfaces diverging toward the inner surface of the one wall, the flame-shaping surfaces of bricks at differing circumferential locations about the throat opening diverging at differing degrees.

2. The invention of claim 1 wherein at least a portion of the combustion chamber boundary is formed by two intersecting planar walls and wherein the flame-shaping surfaces of bricks adjacent last said wall include a surface portion that negatively diverges toward the inner surface of the one wall so that the flame is deflected along a path substantially parallel to last said wall.

3. The invention of claim 1 wherein a portion of the combustion chamber boundary includes a wall closer to the throat opening than other portions of the boundary, and wherein the flame-shaping surfaces of bricks adjacent last said wall include a surface portion that negatively diverges toward the inner surface of the one wall so that the flame is deflected along a path substantially parallel to last said wall.

4. The invention of claim 1 in combination with a plurality of sectorial refracto tiles disposed in said throat openin between the outer su ace of star one wall and said plurality o bricks, the totality of said tiles forming a portion of said throat and diverging toward said plurality of bricks.

5. in a combustion chamber of the type including a generally vertical front wall that has an outer surface and an inner surface, and side, bottom, and top walls receding generally perpendicularly from the inner surface of said front wall, an improved throat construction for forming a throat opening along an axis extending from said outer surface to said inner surface comprising means forming a generally cylindrical opening in said front wall extending between said inner and outer surfaces, said opening being symmetrical with respect to said axis, means disposed in said cylindrical opening for defining a frustoconical throat opening that is coaxial of the cylindrical opening, said frustoconical opening having a circular opening near the outer surface of said front wall and diverging to a larger medial circular opening. at a plane intermediate the outer and inner surfaces of said front wall, a plurality of sectorial bricks disposed in said cylindrical opening and extending from said medial circular opening into the inner wall surface, said bricks diverging from said medial circular opening to an opening at said inner surface that is generally geometrically similar to the internal shape of the combustion chamber as established by the relative position of said side, bottom, and top walls, said plurality of bricks including first individual bricks disposed in sectors radially aligned with medial portions of the respective walls that diverge at a relatively small angle, said plurality of bricks also including individual bricks disposed in sectors that are radially aligned with intersections of said side, bottom, and top walls that diverge outward at a relatively large angle, the angle of divergence of said bricks being proportional to the radial distance from said throat opening along the inner surface of said front wall to said respective side, bottom, and top walls.

6. The invention of claim 5 wherein said frustoconical throat opening defining means includes a plurality of sectorial refractory throat tiles disposed in said cylindrical opening adjacent said outer wall surface, said tiles being configured so that the plurality defines an outer circular opening near the outer surface that diverges to a larger medial circular opening at a plane approximately midway between said outer and inner openings.

7. The invention of claim 1, wherein the degree of divergence of each said brick flame-shaping surface is proportional to the distance from said brick surface to the boundary of the combustion chamber, said distance being measured radially with respect to said throat. 

1. In a combustion chamber bounded by refractory walls through one of which eXtends a throat opening between the outer and inner surfaces of the one wall to admit fuel and air into the combustion chamber, the improvement comprising a plurality of sectorial refractory bricks so disposed that the totality of said bricks form at least the portion of the throat adjacent the inner surface of the one combustion chamber wall, each said brick having a flame-shaping surface thereon, the flame-shaping surfaces being disposed in circumferentially spaced relation to one another so that the totality of the surfaces form at least the inner portion of the throat opening, said brick flame shaping surfaces diverging toward the inner surface of the one wall, the flame-shaping surfaces of bricks at differing circumferential locations about the throat opening diverging at differing degrees.
 2. The invention of claim 1 wherein at least a portion of the combustion chamber boundary is formed by two intersecting planar walls and wherein the flame-shaping surfaces of bricks adjacent last said wall include a surface portion that negatively diverges toward the inner surface of the one wall so that the flame is deflected along a path substantially parallel to last said wall.
 3. The invention of claim 1 wherein a portion of the combustion chamber boundary includes a wall closer to the throat opening than other portions of the boundary, and wherein the flame-shaping surfaces of bricks adjacent last said wall include a surface portion that negatively diverges toward the inner surface of the one wall so that the flame is deflected along a path substantially parallel to last said wall.
 4. The invention of claim 1 in combination with a plurality of sectorial refractory tiles disposed in said throat opening between the outer surface of said one wall and said plurality of bricks, the totality of said tiles forming a portion of said throat and diverging toward said plurality of bricks.
 5. In a combustion chamber of the type including a generally vertical front wall that has an outer surface and an inner surface, and side, bottom, and top walls receding generally perpendicularly from the inner surface of said front wall, an improved throat construction for forming a throat opening along an axis extending from said outer surface to said inner surface comprising means forming a generally cylindrical opening in said front wall extending between said inner and outer surfaces, said opening being symmetrical with respect to said axis, means disposed in said cylindrical opening for defining a frustoconical throat opening that is coaxial of the cylindrical opening, said frustoconical opening having a circular opening near the outer surface of said front wall and diverging to a larger medial circular opening at a plane intermediate the outer and inner surfaces of said front wall, a plurality of sectorial bricks disposed in said cylindrical opening and extending from said medial circular opening into the inner wall surface, said bricks diverging from said medial circular opening to an opening at said inner surface that is generally geometrically similar to the internal shape of the combustion chamber as established by the relative position of said side, bottom, and top walls, said plurality of bricks including first individual bricks disposed in sectors radially aligned with medial portions of the respective walls that diverge at a relatively small angle, said plurality of bricks also including individual bricks disposed in sectors that are radially aligned with intersections of said side, bottom, and top walls that diverge outward at a relatively large angle, the angle of divergence of said bricks being proportional to the radial distance from said throat opening along the inner surface of said front wall to said respective side, bottom, and top walls.
 6. The invention of claim 5 wherein said frustoconical throat opening defining means includes a plurality of sectorial refractory throat tiles disposed in said cylindrical opening adjacent said outer wall surface, said tiles being coNfigured so that the plurality defines an outer circular opening near the outer surface that diverges to a larger medial circular opening at a plane approximately midway between said outer and inner openings.
 7. The invention of claim 1, wherein the degree of divergence of each said brick flame-shaping surface is proportional to the distance from said brick surface to the boundary of the combustion chamber, said distance being measured radially with respect to said throat. 